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Why is my AC unit making weird noises?

Estes Services 

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Are you wondering, Why my AC is making weird noises? In this article, we will go over common weird noises that could be coming from your AC that are abnormal and require attention.

An AC making weird noises is not only annoying but can also lead to larger problems down the road if left unchecked. That's why it's important to know the common noises that indicate you may need an AC repair service or replacement.


First and foremost, rattling noises can indicate that loose objects are coming into contact with the unit. For example, such loose objects could be leaves, twigs, or rocks. Or, parts of the unit (e.g., panels, screws, bolts, etc) have come loose. If this is the case, more parts could become loose, causing even more problems and long-term damage.

Additionally, a rattling noise could be caused by a malfunctioning compressor. In this scenario, you will likely notice that your home is not cooling as effectively as it once did. Compressor problems should be left to diagnosis by a licensed and trained professional.

Further, when you have rattling noises, you could also have to malfunction AC motors caused by damaged bearings or poor lubrication. There could also be misaligned fan blades in your unit. Again, under these scenarios, you will want an HVAC professional to diagnose.

As you can see, there could be numerous explanations behind rattling noises. Thus, if your AC is making such noises, it's time to have a licensed air-conditioning technician inspect your unit, identify why the noise is happening, and fix it accordingly.


If you hear a buzzing sound from your AC unit when it's running outdoors, this should not be overlooked, as it can indicate an electrical problem with your unit. There could be a problem with your components, such as a faulty condenser fan motor, faulty compressor, or isolation feet issues.

If you hear a buzzing noise from the indoor air-conditioning unit, you could have an issue with frozen evaporator coils. It's best to have a licensed professional perform a proper diagnosis for a buzzing noise.


Are you hearing new squealing noises from your unit? This may be from a mechanical issue such as a worn-out compressor, fan motor, or blower motor. Additionally, worn-out fan belts can cause squealing.


Hissing noises are also not normal.

Hissing could indicate an air duct leak in your home. This noise could also indicate a refrigerant leak. The refrigerant in your AC unit is under pressure, so, when it leaks, it makes a hissing noise, which should not be ignored. The longer you let a refrigerant leak fester, the likelihood of larger problems and costlier repair bills.

When you hear hissing, it's time to schedule service with an Atlanta HVAC technician.

Grinding Noise

A grinding noise is a serious noise that can be a cause for concern. If it's coming from an outdoor air conditioner unit, it could be from the following:

compressor issues;

a loose blower fan belt;

or lack of motor lubrication.

A grinding noise is reflective of the need for AC services, and you should have a professional properly remedy the problem.

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There you have it. The answer to the question, "Why is my AC making weird noises?" From buzzing to squealing, rattling to hissing, there are a lot of weird noises that your AC unit can make that could indicate the need for immediate AC repair service.

It's better to be safe than sorry. If you're noticing weird noises coming from your AC unit, it's time to get your comfort and peace-of-mind back with the help of our experienced HVAC professionals at Estes Services.

For over 70 years, the greater Atlanta area has trusted us for home comfort needs. Our knowledge and experience in AC services enable us to provide you with top-quality AC repair consultation. Schedule service today.